Sunday, February 26, 2017

The traditional incandescent bulbs claim a 800-1000 hour life. That's the best compromise between light per watt hour and bulb life. They sell long life incandescent bulbs, and they do last longer, but they don't give much light. A 60 watt conventional bulb throws as much light as a 100 watt long life bulb. 800-1000 hours for say a living room lamp that goes on at sundown and burns til bedtime, is 200-300 days, call it a year.
The curly bulbs claim 8000 hour life, ten times the life of an incandescent. That ought to mean ten years service life.
And I suppose some curly bulbs do last that long. A lot of 'em don't. I have had at least four, die in place after only a year or two of service. That's out of a total of 8 curly bulbs in my house. Half the population of curly bulbs dies young. Mostly the dead ones come out of the fixture with a burn mark on the base, suggesting that some electronic part inside the solid state ballast has failed, rather than the glowing curly tube. Let's guess that the marketeers who pushed for the 8000 hour life claim were thinking that the only part that could fail was the curly tube, analogous to the filament in an incandescent bulb. Solid state ballast failures were ignored.
On the other hand, as a homeowner, I don't care why the curly bulb died, I gotta replace it for $5 or live in the dark. But I do think anyone computing lifetime costs of incandescent vs curly bulbs ought to call the curly bulb life as 4000 hours rather than the 8000 hours marked on the package.